Apparatus for and method of twisting and plying strands



July 7, 1959 APPARATUS FOR Filed Sept. 5, 1956 gym. L8 46 2 ,4/ A; a- I l I/ A. W. VIBBER 2,893,197

AND METHOD OF TWISTING AND FLYING STRANDS 5 Sheets-Sheet 1 FNVENTOR.

Way

July 7, 1959 w BBERA 2,893,197

APPARATUS FOR AND METHOD OF TWISTING AND FLYING STRANDS Filed Sept s, 1956 I 5 She et's-Sheet 2 INVENTOR.

July 7, 1959 A. w. VIBBER 2,893,197

v APPARATUS FOR AND METHOD OF TWISTING AND FLYING STRANDS Filed Sept. 5, 1956 1 5 Sheets-Sheet 3 INVENTOR.

July 7, 1959 v A. w. VIBBER 2,893,197

APPARATUS FOR AND METHOD OF Twr s'rmc AND FLYING STRANDS Filed Sept. 5. 1956,

5 Sheets-Sheet 5 INVENTOR.

United States Patent APPARATUS FOR AND METHOD OF TWISTING AND PLYING STRANDS Alfred W. Vibber, Ridgewood, NJ.

Application September 5, 1956, Serial No. 608,137

33 Claims. (Cl. 57-583) This invention relates to an apparatus for and method of twisting and/or plying strands. More particularly, in certain aspects of the invention the apparatus and method relate to the plying of strands together by rotating one strand about a source of another strand by a revolving shaft and plying the strands together beyond such source of the other strand, whereby the strands are twisted about each other without the addition of twist to either of the strands themselves. Such apparatus is sometimes referred to as skip type plying apparatus.

In certain twisting apparatus of the type above indicated two driven feeding means are employed to forward the one strand into the balloon and the other of the strands toward the point at which the strands are plied together, the two feeding means being driven at the same strand forwarding speed and in synchronism with the revolving shaft. Such apparatus requires that the taking-up of the plied strand be carried out at a generally constant tension and thus at a variable speed, which is not synchronized with the speed of rotation of the revolving shaft. Consequently, since the number of twists per unit of'length of the plied strand depends upon the rate at which the two strands are twisted about each other as they travel from the plying point to the first fixed guide outside the spindle, the number of twists per unit length of plied strand is inherently non-uniform. Such non-uniformity of twist of the product makes it somewhat less desirable than a uniformly twisted strand would be in articlessuch as automobile tires, V-belts, hoses, and the like, in which such strands are employed for reinforcement. Further, difiiculty has been experienced with such type of plying apparatus in maintaining the balloon with a desired narrow range of diameters. Undue variation in balloon diameter is, of course, undesirable since it changes the rate of absorption of the ballooned strand into the plied strand.

The present invention in certain aspects thereof provides an apparatus and method, of the general character first indicated above, such apparatus having two retarded strand metering means connected to allow the passage of each of the strands to the plying point at the same speed.

Such metering means are not driven in synchronism with the revolving shaft, but are retarded and are impelled in the strand forwarding direction by the action thereon of their respective strands as they travel therepast. The respective strands are pulled past their metering means and toward the plying point by the plied strand as the latter is fed at constant speed out of the plying spindle. In the apparatus of the invention one strand metering means is positioned outside the balloon, and forwards the one strand into the balloon. The other metering means is located inside the balloon, and forwards the other strand from itssource of supply toward the plying point. The apparatus of the invention provides novel means for connecting the two strand metering means together whereby they are caused to rotate with a predetermined strand forwarding speed ratio with respect to each other at all times. In the making of plied strands for use in automobile tires such speed ratio is usually 1:1. Because a part of the connecting linkage between the two metering means lies outside the spindle and is thus readily accessible, a manually or otherwise adjustable retarding means may be applied thereto, whereby the retardation of both metering means may be changed, when necessary, to the same extent. The constant speed means taking up the plied strand from the spindle of the invention is preferably one driven at a fixed ratio with relation to the speed of rotation of the revolving strand-plying shaft.

The plying apparatus of the invention has the prop erty of being self-compensating at least to a large extent as to variations in balloon diameter. When the balloon increases in size, more of the ballooned strand is automatically absorbed into the plied strand, thereby to reduce the diameter of the balloon to its optimum value. The reverse action takes place when the balloon decreases unduly in diameter, the ballooned strand then being absorbed in the plied strand at a slower rate, whereby the balloon is increased to its optimum diameter. Balloon control devices such as will be pointed out hereinafter may, however, be employed with the apparatus in order to reduce the range through which the balloon diameter varies during operation of the apparatus.

The invention has among its objects the provision of.

an improved apparatus for and a method of plying strands together.

Another object of the invention lies in the provision of plying apparatus of the skip type which is self-compensating as to variations in balloon diameter.

The invention has as a further object the provision of an improved apparatus and method of the type indicated wherein one retarded strand metering means is employed for the first, outer strand in advance of its balloon, and

a second such means is employed for the second, inner strand in advance of the plying point, the two strandmetering means being connected so that they are caused to forward their respective strands at a definite predetermined speed ratio with respect to each other.

A further object of the invention lies in the provision of a twisting and/or plying spindle having a strand speed-governing means within its balloon, such spindle incorporating connecting or linkage means effectively extending from outside to inside the balloon, whereby the strand speed-governing means may be controlled from outside the balloon while the spindle is in operation.

Yet another object of the invention lies in the provision of a twisting and/or plying spindle having a strand metering or forwarding means within its balloon, such spindle incorporating connecting or linkage means where-1 by the metering means may be controlled from outside the balloon while the spindle is in operation.

A further object of the invention in certain embodiments thereof lies in the provision, in a spindle of the character indicated in either of the two preceding paragraphs, of a novel mechanism, formed at least in part of the connecting or linkage means, for preventing turn-;

ing in space of the strand package within the balloon and the support for such package.

The above and further objects of the invention relat-' ing to economics of manufacture and use of the apparatus and advantages of practice of the method will more fully appear upon consideration of the following specification, and of the accompanying drawings forming a part thereof, in which:

Fig. 1 is a somewhat simplified, partially schematic" view in vertical axial section through the plying spindle of a first embodiment of plying apparatus of the inVen-' tion, certain parts of the apparatus being shown in elevation, 1

of Fig. l, the view'being partially in side elevation taken from the pointof view of line 3-3 inFig; 1,.the take-up capstanand package winding means for the plied strand being. shown displacedfrom their actual position forclar'ity'of illustration.

Fig; 4 isa horizontal section through the apparatus of Fig. 1-, the section beingtaken generally alongthe lilJBl44- of Fig; l.

" Fig; 5 isa fragmentary view-in ve'rtical section along;

lined- 5 of Fig. 4.

Fig. 6 is a diagrammaticasket'ch of the apparatus to. allow the" self-compensating. action:- ofthe apparatus to be more simply explained;

' Fig. 7 is a somewhatsimplified schematic view in vertical axial section through a second: embodiment of plying-j spindle in accordance with the invention, certain parts of the apparatus being shown in' elevation;

Fig. 8 is an enlarged; view in vertical axial section through-a portion of thefiyer and inner strand metering means of the apparatus of Fig; 7,.- certain parts of the apparatus being shown in elevation;

Fig. 9- is a frag-mentary'view partially in vertical section and partially in side elevation of a second embodiment ofi magnetic torque-transmitting coupling. which may be employed between the inner and outer strand-metering means, the section beingtaken generally along line 9-9 ofiFig-IO; I 1

Fig. 10 is a view in end elevation of one of the main parts: of the second embodimentof torque-transmitting coupling; the elevation being taken from line 10-10 of Fig. 9,- a portion of the fixed guard associated withsuch coupling part beingshown in elevation.

Fig; ll is a viewsimilarto Fig. 9 of a third embodiment of magnetictorque transmitting couplingwhich may be employed between the inner and outer strand meter ing means of the apparatus ofthe invention, thesectionbeing taken generally along line 11'-11-of Fig. 12;

Fig; 12' is aview similar to Fig; 10 of such third embodiment of-magnetic' coupling, the elevation being taken generally along line 12-12 ofFig. 1 1

Referring first to Fig. 3; the'p1yinghppara'tus and method of the first er'nbodimentof the invention will be briefly described. A first, outer, strand 1!} is fed from afirst, outer let-off strand-packageorstorage means 11 upwardly through a first retarded strand-metering means 12 over one or more intermediate guide pulleys; to an idle guide pulley 14,; located above theplying spindle, which is generally" designated 13 Strand 10' enters balloon 16 through a guiding eye 15, and after traveling through the balloon enters flyer 17 and progresses radially thereof" in run 18'- tOtlit; plying POint P, where" it'- meets strand 20 from the second,- inner strand let-off package or storage mean's 19.- In its travel from package 19 to po'in't' P; strand 20 passesthrough the second, inner,

retarded s'trand rr'ietering mean's 212- Theplied strand 22 is pulled downwardly through the driven hollow fi'y'ersupporting central shaft ofthe spindle over guide pulleys to the take-up capstan 24 which is positively driven insy nchronism with the rotationof the fiyer 1 7, and after delivery from the capstan 24 is" wound upon a bobbinby meansindicated generally at 25'? The firstand second strand-meteri'ng means- 1-2- and 21,

respeeti-beiy, are connected, as-sh'ewn 11 Figs. 1 2 and 3 and to" be exr'fla'ined more fully hereinafter, by means iriclr'lding magnetic couplings 28; which causes thetwo'- posedof the twostrand-metering means 12 and 21 andtheir connecting linkage is preferably retarded by't'wo" retarding means such as separate brakes, one of which is located inside the balloon and the other of which is located outside the balloon Strand-metering means 12 and 21 are mutually controlling and exchange energy between themselves, as will appear hereinafter; also, because of the inherent decrease in tension in the strand above the eye of a downtwist'er as the balloon increases in. diameter within the operative balloon diameter range and the inherent increase in' such tension as the balloon decreases in diameter; means 12 and 21 function to compensate automatically for variations in balloon diameter.

Taking up now the apparatus of Figs. 1, 2, 3 and 4 in detail, the plying's'pindle' 13: includes a main hollow shaft 26 rotatably supported-in bearings 27 mounted in frame parts 29. Shaft 26 is driven at high speed, as by a constant speed motor, not shown, through a belt (also not shown) entrained over pulley 30 on the shaft. The upper end ofshaft 26 isenlarged to form the fiyer I7. Rotatably supported on the flyer in bearings 32, so as to-remain held from rotation with the shaft by means to be described, is ahollow column 34, which supports a platform 35 non-rotatably aflixed thereto, a central arbor 36' afiixedto the platform, and the (second) retardedstrand metering means,v generally designated 21', for governing the speed of paying 01f ofthe inner strand 20 from the inner package 19; Package 19 is rotatably' mounted on arbor 36' by bearings 37, so that the packagemay'rotate at the speed required by the paying. off of strand 20therefrom. Such strand is led through guiding eye 39 affixed to the edge of platform 35 inits travel fromthe package to strand metering. means 21'.

The strand meteringv means 21 consists of a pair of multigrooved horizontal parallel capstan rolls disposedone. abovethe other, the-upper roll being designated 40- and the, lower roll being designated 41, such rolls being jo'urnalled in a housing 42. Strand 20 is led from eye 39- into a side groove on roll 40 and thence to aside groove on roll 41, being thereafter transferred from groove to groove of the two rolls until it reaches the axis of shaft-26, after which' it is fed downwardly to point P. Sufficient wraps of strand 20 about rolls 40 and 41- are taken to insure substantial non-slipping engagement between the strand and the rolls, which, as explained-below, are positively connected together to revolve at the same surface speed.

Each ofrolls 40 and 41 has aifixed thereto at eachend a gear 44 which meshes with a respective pinion 45 on-a horizontal shaft 46 passing between rolls 40 and 41' and journalled and held against endwise movement in' the ends of housing. 42. Thus the speed of rotation of shaft 46' governs the strand metering speed of means 21 Intermediate the length of each end of shaft 46 beyond housing 42 the shaft isrotatably carried by depending supports 47 on platform 35.

Strand metering means 21 is preferably retarded primarily by a manually adjustable brake, generally desig nated 33. Such brake, which is most clearly shown in Fig. 2, has a brakeshoe 3'8-which acts upon the ungrooved right hand end of upper capstan roll 40. The brake shoe is guided in a passage on theframe ofmeans21', and is pressed uponroll 40with a force which may be adjusted by' turning thumb screw 43, which is threaded into a bracket attached to the frame of means 21. The degree oficompression'of a' coil compression spring 48', interposed between thumb screw 43 and theibrake shoe 38, determines the retarding torque which the shoe 38 exerts on themetering means 21.

Ina zone includinglthe largest-diameter of the balloon. somewhat nearerthe flyer 17 than we 15, the balloon" has a shape in the operative range thereof whichis roughly ofthe shape ofthat section of a sphere formedby t wo spaced parallel planes transverse to an axis ofanimaginary sphere, such axis: coinciding with the axis of theballo'o'n and located equal: distances from: each ele of the sphere; The shafts 46 and 54' arelo'ca'tedso as to'ilie generally in the, plane of the equator of such zone. A magnetic coupling means effectively synchronously connects each end of shaft 46 to the end of the respective shaft 54. One embodiment of such coupling means, there designated generally as 28, is shown in Figs. 1-5, inclusive. It will be apparent that other magnetic couplings of different construction, such as shown in Figs. 912, inclusive, to be described, may be substituted for the couplings 28.

Couplings 28 are constructed as follows. Each outer end of shaft 46 carries a similar outwardly convex disclike member 49 disposed coaxial of the shaft, each forming a part of its respective magnetic coupling 28, members 49 being made of thin non-magnetic material such as brass. Specifically, discs 49 are formed as that section of a second imaginary sphere symmetrically disposed on said pole of the first sphere formed by scribing a circle of smaller diameter than the second sphere on the surface of the second sphere, the second sphere having a diameter which is somewhat smaller in diameter than the smallest diameter of the operative range of diameters of balloon 16. Members 49 are located so as to lie inwardly beyond balloon 16 on such second sphere when such balloon is at its smallest operative diameter. Thus during normal operation of the spindle 13 the balloon 16 always remains spaced from, but close to, the outer face of members 49. As will be clear hereinafter, the operative-range of variation of diameters of balloon 16 is relatively small.

Members 49 serve as supports for a plurality (four shown on each member 49) of fixed magnets 50, made of Alnico orthe like, mounted at equal angular spacings about the inner edge of each member 49. Each member 49 and its magnets 50 serves as the inner part of the mag netic coupling 28 between the inner (21) and outer (12) strand metering means, as will appear. To insure that the strand 10 in balloon 16 will not normally contact members 49, there is preferably employed a wire protective cage, made of non-magnetic metal, which surrounds the platform 35 and is attached thereto, as shown. Such cage has an upper circular rod 51 and a lower circular rod 52 which lie close to above and below, respectively, the outer edges of members 49, and at least slightly radially outwardly beyond the surface of the second imaginary sphere on which the outer surfaces of members 49 lie.

The other, outer, portion of each of the magnetic couplings 28 between the inner metering means 21 and the outer metering means 12 is made up of an outer shaft 54 which is aligned with and lies outwardly of the end of the respective shaft 46, disc-like member 56, and magnets 57. Shafts 54 are rotatably supported and held from endwise movement in frame parts 55. The inner end of each of shafts 54 has afiixed thereto in coaxial relationship the outer disc-like member 56 lying radially outwardly of the balloon. Members 56 are made of nonmagnetic material such as brass, and carry on the edges of their outer surfaces fixed magnets 57. Outer magnets 57 are the same in number and are angularly spaced about members 56 in the same manner as inner magnets 50.- Magnets 50 and 57 are made of such relative polarity that when they confront each other as shown, they act across the relatively narrow balloon-passing gap between them to, lock shafts 46 and 54 together for joint rotation and successfully resist any unlocking forces (to be discussed) exerted on them during normal operation of the spindle. Thus shafts 54 may be made to control the speed of r otation of rolls 40 and 41 of the inner strand metering means 21.

Disc-like outer members 56 are formed as circular sections of a third imaginary sphere, such third sphere being of .such diameter and members 56 being so located that their inner surfaces lie at least slightly radially outwardly beyond the largest operative diameter of balloon 16, so

that}! Will not be nontacted by the balloon. To. insure that members 56 will not be touched by the balloon, there is preferably employed an outer wire guard made of non-magnetic metal, such outer guard being connected to fixed frame parts 29 and 55, as shown, and having an upper circular rod member 59 and a lower circular rod member 60 lying close to the upper and lower edges, respectively, of members 56, and lying radially at least slightly inwardly of such edges.

Not only does each of the sets of members 49, 56 with their magnets function to connect metering means 21 to controlling outer shafts 54, but it also functions to maintain platform 35 from rotation in space because of the strong attraction between magnets 50 which, in effect,

are attached to platform 35, and magnets 57, which, in effect, are attached to the fixed outer frame parts 55. In some instances the magnetic couplings 28 may be em ployed as the only means for maintaining package and its supporting platform from turning about the axis of the shaft. In other cases the platform may be eccentrically weighed and the spindle tipped at a small angle to the vertical and/or a holding magnet system such as that shown in Clarkson Patent No. 2,729,051 may be used to supplement the package and platform' holding effect of magnetic couplings 28.

The remaining parts connecting the capstan rolls of metering means 21 for joint rotation at the same speed with the capstan rollers of metering means 12 will be more clearly understood by reference to Figs. 3 .and 4. The outer ends of shafts 54 are connected by similar bevel gear sets 61 to cross shafts 62 which in turn are connected through similar bevel gear sets 64 to the oppo site ends of shaft 65. It will be understood that shafts 62 and 65 are rotatably mounted in suitable fixed framework, parts of which are generally indicated. Since it is here desired that the two strand metering means 12 and 21 shall have the same effective strand-forwarding speed, the means 12 and 21 are such, and the gear sets 61 and 64 are such, that when the rolls 40 and 41 of means 21 turn, the strand-engaging rolls of means 12 and 21 will turn at the same peripheral speed. Prefer ably, for convenience, means 12 is made identical with means 21, and shafts 65 turns at the same angular speed as shafts 54.

Shaft 65 carries two small longitudinally spaced pinions 66 (one shown in Fig. 3) which mesh with gears at opposite ends of the upper and lower multi-grooved capstan rolls 67 and 69, respectively. Strand 10 engages rolls 67 and 69 non-slippingly, and progresses from roll to roll in the same manner as does strand 20 in strandmetering means 21.

A manually adjustable retarding means 70, generally similar to means 33, acts upon a brake drum 71 aflixed to shaft 65. Means 70 includes a brake shoe 72 urged against brake drum 71 by a thumb screw 74 acting through a coil compression spring 75.

The separate retarding means 33 and 70 for strandmetering means 21 and 12, respectively, are each preferably adjusted so that each exerts at least slightly more retarding force on its respective metering means than is required to keep such metering means from being overpowered by the tension of its respective strand at any time during operation of the apparatus. Thus, brake 70 is adjusted to exert at least a slightly greater retardation on means 12 than such means is ever called upon to exert to hold the balloon within its desired operative diameter range. Brake 33 is adjusted to hold strand 20 substantially under a desired tension during operation of the device. Once brakes 33 and 70 have been adjusted they need not be further adjusted for long periods of operation of the apparatus.

Because each strand metering means 12 and 21 preferand 21 with a 1:1 speed ratio, are called upon to transmit 1 only a relatively small driving torque through them, such driving torque being only that necessary to exchange sulficient energy from means 12 to means 21, or vice versa, to maintain means 12 and 21 locked in synchronism at all times. The torque required to be transmitted through the magnetic couplings 28 is made smaller by making the pin-ions on the central shafts 46 and 65 of metering means 21 and 12, respectively, of small diameter with respect to the diameter of the gears on the multigrooved capstan rolls with which such pinions mesh.

' It will be apparent from the above that plied strand 22 is pulled from the spindle at a constant speed which is synchronized with the constant speed of rotation of the flyer, thereby to yield a plied strand with the desired number of twists per unit length. It will also be apparent that the two strands approach the plying point at equal speeds, except for the small inevitable creep of the strands on metering means 12 and 21.

' The self-compensating function of the apparatus, whereby the balloon 16 is automatically maintained with a'- narrow range of diameters, will be more readily understood upon consideration of the diagrammatic sketch in Fig". 6. In Fig. 6, for simplicity, the run of inner strand 20 is laterally displaced from balloon 16, and the connectingmeans including shafts 46, 54, etc., and magnetic couplings 28 is shown as extending directly between the diagrammatically illustrated metering means 12 and 21.

The tension existing in each of the various parts of the strands is designated by a t with the reference chara'e'te'r number of such part as a subscript, the back tension exerted by brake 33 is designated R and that exerted by brake 70 is designated R- Before discussing variations in tension, the relationships which exist at all times will be given:

Equation 1 is axiomatic. Equation 2 follows from the fact that the strand has marked frictional engagement with eye..1 and the radially outer edge of the passage in flyer 17, both such engagements adding appreciable retarding force to the outer strand as it travels toward plying point P. Stated in another manner, as to the engagement with eye 15, there is a snubbing action whereby a smaller tension :above the eye in efiect balances the larger tension of the balloon, as to the engagement with the flyer, the larger the balloon the greater its wrap-around, and thus the greater angle which the lower end of the balloon makes with the outer end of the radial passage in the flyer. Equation 3 is axiomatic.

. It will first be assumed that balloon 16 is of the optimum desired diameter, and that brakes 33 and 70 have been adjusted to exert the proper retardation on the two strands to cause the apparatus to operate stably to ply runs 18 and of the two strands together at substantially equal tensions, and .for I to have the desired value. Under such conditions strands will lie symmetrically in [plied strand 22.

Let us now assume that, because of the above-discussed inevitable creep of the strands on their metering means 12 and 21, the balloon 16 tends to increase in diameter. This in turn causes t to decrease. But R33+R70 is a constant. Therefore the increased force to turn means 12, 2-1, 28, etc. must come from strand 20, in other words r rises. When 1 t strand 20 tends to become the core in the plied strand, and a greater length of strand 101than of :strand 20 is then absorbed into the plied strand. The excess length of strand in balloon 16 is thus quickly taken up, and balloon 16 is restored to its optimum diameter, at which t =t Thereverse action occurs when balloon .16 contracts unduly. Tension 'tm then increases, the tension t decreases 1:9 .20, strand 10 tends to become the core .in theplied strand, and thus .less of strand 10 than strand 8 20 is absorbed into strand 22, and balloon 16 is quickly restored to its optimum diameter at which 1 :1

Because of the above-described self-compensating ac tion of the device it is not necessary to employ with the apparatus any additional balloon-controlling device. However, it may sometimes be advantageous, in order further to decrease the range of variation of the diameter of the balloon, to employ a self-adjusting eye, instead of eye 15, such as that shown and claimed in app'licants application $617. No. 261,704, filed December 14, 1951 or that shown in Clarkson- Patent No. 2,689,449, September 21, 1954. Both such self-adjusting eyes operate in the combination herein disclosed to maintain the balloon diameter within close limits by decreasing the height of the balloon when the balloon diameter increases unduly and to increase the height of the balloon when balloon diameter decreases unduly. As alternatives to use of such self-adjusting eyes, the flyer 31 of the present apparatus may be provided with devices such as shown in applicants Patent No. 2,727,353 or his application Ser. No. 450,358, filed August 17, 1954, now US. Patent No. 2,814,925, whereby to maintain the diameter of the balloon within close limits.

A second embodiment of the plying apparatus of the invention is shown in Figs. 7 and 8. Such apparatus functions in generally the same manner asthat of Figs. 1-5, inclusive. The main difference between the two embodiments is the wholly mechanical connection employed in the latter between the inner strand-metering means 21 and the outer strand metering. means 12'.

The spindle 13 of Figs. 7 and 8 has a fiyer 17 made as an enlarged head on hollow driven main shaft 26', such shaft being rotatably supported in bearings in frame parts, as shown. .A constant speed take-up capstan 24 for plied strand 22 is driven. by shaft 26' through the medium of a worm 76 on shaft26' meshing with a worm gear 77 which drives means 24'. Plied strand 22' is taken up at 25' after leaving capstan 24'.

Rotatably supported on flyer 17 is a column 79 hearing a platform 80 serving as the support for inner let-ofi package 19'. Column 79 and platform 80 are held from rotation by a conventional annular outer fixed magnet system 81, aflixed to a frame, not shown, and an inner annular magnet system 82, spaced from means 81, and attached to platform 80.

The inner strand-metering means 21 is located within column 79 and is attached thereto so as to be non-rotatable in space. Means 21' has spaced multi-grooved capstan rollers 84 geared together, rollers 84 being driven by the passage of strand 20' from package 19, as the strand non-slippingly engages the capstan rollers 84 and travels to plying point P under the pull of means 24' acting through plied strand 22'.

The outer strand-metering means 12' has two multigrooved capstan rolls 85, one of which is integrally connected to the lower end of a hollow shaft 86 rotatably mounted within shaft 26' by bearings 87. The .two multigrooved capstan rolls of means 12' are geared together, as shown. Strand 10' non-slippingly engages rolls 85, and then passes over appropriate guide pulleys up and then down into the guiding eye for balloon 16'. Strandmetering means 12', as well as means 21' which is dn'vingly connected thereto by a means to be described, is retarded by an adjustable brake 89 applied to a brake drum on one of rolls 85.

Means 12 and 21' are drivingly connected as follows: an upper hollow tube .90 is rotatably mounted in bearings 91 on the upper end of dyer 1.7 coaxially thereof. The upper end of tube 99 is necked in at the top, and has a spiral bevel gear 92 cut thereinto. Meshing with gear .92 is a central spiral bevel gear 94 on an intermediate gear member 95 rotatably supported in column 7.9. The outer ends of member 95 bear pinions which mesh with the gears on the .outer ends of the capstan rolls 84. The construction of capstan .21" is such that strand 20' is'first brought down thereinto at side grooves in rolls 84, and then progress from groove to groove toward the axis, finally leaving and travelling down through tube 90, a central opening in flyer 17' where it meets strand at plying point P, and thence (as a component of plied strand 22') axially of the spindle down through hollow shaft 86 to guide pulley $6.

Hollow shaft 86 and tube 90 are positively mechanically connected for equal angular motion, assuming that a 1:1 speed ratio of means 21 and 12' is desired and that such two means are to travel at the same peripheral speed. Such mechanical connection is formed by annular gears 99 and 100, on the upper end of hollow shaft 86 and lower end of tube 90, respectively.

Eccentrically journalled in flyer 17 diametrically opposite the radial passage conducting strand 10 is a short vertical shaft 101 having pinions 102 and 104 meshing with annular gears 99 and 100, respectively. Such connection allows hollow shafts 86 and 90 to have a 1:1 driving relationship through the rotating fiyer without being driven by the iiyer. Thus such second described embodiment of the apparatus likewise has the inner and outer strand metering means driven only by .the tension of the respective strands pulled therepast. Such two strand-metering means exchange energy between them as in the first embodiment, and thus function automatically to maintain the balloon within the desired operating range of diameters.

The apparatus of the invention may be employed, if desired, with variable strand tensioning means, responsive to variations in tension of the strand to correct such variations, instead of the above described (1) adjustable retarding means 33 or (2) the above described adjustable retarding means 70. In such alternative plying devices land 2, now to be described, the sum of the retardations imposed upon strands 10 and 20 is not a constant but varies in armanner to be described in connection with each of devices 1 and 2.

(1) In alternative device 1, strand retarding means 33 remains the same as in the apparatus of Figs. 1-5, inclusive. For strand retarding means 70 of such apparatus, however, there is substituted a variable strand retarding means of the same general character as that shown in Figs. 1 and 2 of Truitt Patent No. 2,586,123, but altered to cause the yielding tension sensitive means which diverts the strand into a salient path to engage the strand 20 between the variable strand retarding means and the plying junction P, and also altered so that as the tension in strand 20 at the tension sensitive means rises the variable strand retarding means imposes a still greater retarding tension on strand 20. Preferably the variable strand retarding means and its associated tension sensitive means are so constructed that when the tension in strand 20 lies below a predetermined value the retarding effect of the variable strand retarding means is a constant, so related to the adjusted value of means 33 as normally to hold the respective strands under first, desired tensions for normal stable operation of the sys tem, and that when rises appreciably above its first value the variable strand retarding means raises I to progressively larger values. The construction and adjustment of retarding means 33 remains the same as in Figs l-5, inclusive, and means 33 is drivingly connected to the variable strand tensioning means in the same manner as means 33 and 70 in Figs. 1-5, inclusive.

In this manner, the self-compensating function of the apparatus is accentuated.

(2) In this alternative apparatus, retarding means 70 remains the same as in Figs. 1-5, inclusive. A variable strand tensioning means is substituted for retarding means 33. Means 70 is drivingly connected to the variable strand tensioning means in the same manner as means 33 and 70 in Figs. 1-5, inclusive.

The variable strand tensioning means of this embodignent is constructed in generally the same manner as the sioning means and between such means and guiding eye 15 for balloon 16. The variable strand tensioning means and the tension sensitive means associated therewith are so constructed that as the tension in the strand 10 at the tension sensitive means decreases below a predetermined desired value the retardation imposed upon strand 10 by the variable strand retarding means is progressively increased, and that when the tension in strand 10 at such zone lies at or above such desired value the variable retarding means imposes a constant retardation on strand 10, suitably adjusted and related to R as normally to hold the system in stable operation.

In Figs. 9 and 10 there is shown a second embodiment, and in Figs. 11 and 12 there is shown a third embodiment of magnetic coupling between the inner and outer strand-metering means. Each of such coupling means is designed to be substituted for one or both of magnetic coupling means 28 in the embodiment of the apparatus shown in Figs. 1-6, inclusive.

In Fig. 9 there is shown a magnetic coupling means generally designated 28', and adapted synchronously to lock together shaft 46, connected to the inner strandmetering means 21 as in Figs. 1-6, inclusive, to shaft 54, connected to the outer strand-metering means 12, likewise as in Figs. l-6, inclusive. Means 28 is made up essentially of two generally similar confronting integral Alnico bodies 106 and 107, between which the strand 16 of the balloon rotates. Both these bodies are in the form of hollow circular cylindrical bodies disposed coaxially of the shafts 54 and 46 to which theya-re connected by means 56 and 49, respectively. The end of element 106 which confronts element 107 is deeply cut by radially disposed grooves or scallops 104 to provide a plurality (four shown) of angularly spaced longitudinally ex! tending pole pieces 101, 102. Pole pieces 101 are shown as being north (N) poles and pole pieces 102 are shown as being south (S) poles. 106 present a smooth surface confronting the air gap through which strand balloon 16 rotates, it is preferred to fill the longitudinal passage through the magnet and the scallops 104 therein with a non-magnetic material such as aluminum, copper or similar metal, or with a non-metallic material such as an artificial resin. The member 56' by which element 106 is mounted on shaft 54 may conveniently be made of the same non-- magnetic material and may be made as a casting integral with the material which fills the hollow and scallops in the magnet. Element 106 is the outer member of the magnetic means 28. Consequently it is preferred to make the inner face 100 of element 106 concave and in the form of a part of a sphere, as shown.

As stated, the inner element 107 of the magnetic means 28 is essentially similar to element 106. Member 49', which secures element 107 to shaft 46, may be made integral with the non-magnetic material which fills the central passage in the magnet and the scallops between its poles. The outer face 109 of element 107 is preferably made convex and spherical, and parallel to.

face 100 of element 106.

In the embodiment of Figs. 9 and 10 there are employed an outer guard 110 and an inner guard 111 which are shown as made of a plastic material. The outer guard may be mounted on the fixed frame of the apparatus, and the inner guard may be mounted on the platform 35. Such guards are in the form of portions.

guards and the elements 106 and 107 thus present essen-j In order to have element,

tiallysmooth surfaces to the balloon, so that there is no' chance of :injury 'to the strand even though the balloon should momentarily expand .or contract unduly, as during the starting up of the spindle. Further, such construction allows the gap between magnetic elements to be made relatively narrow.

In 'Figs. 11 and 12 there is showna third embodiment of magnetic torque transmitting device of the invention, which, like that of Figs. 9 and 10, maybe substituted for that of Figs. 1-6, inclusive. In such third embodiment, the magnetic device 115 is made up of two coacting elements 121 and 122 connected to shafts 54 and 46, respectively. Each element includes a non-magnetic supporting disc 119and 120, respectively,-connected to shafts 54 and 46, such discs bearing a generally similar annular sintered ceramic outer permanent magnet 116 and an inner permanent magnet 117. Such magnets are generally the same in structure except that the inner face 124 of magnet 116 is concave and spherical and the confronting outer face 125 of magnet 1 17 is convex and spheri cal. Magnets 116 and 117 are preferably annular in shape, having central passages 126 and 127 therethrough. Such passage may be filled with non-magnetic material such as a resin so that the magnetic elements present smooth unbroken surfaces to the balloon. The magnets are non-rotatably -retained relative to their supporting dics 119 and 120 by sidewalls 129 and 130, respectively, preferably integral with such discs, which snugly engage the magnets. The free edges of such'sidewalls are flanged inwardly at 131 and 132, respectively, into shal low grooves on the edges of the magnets, so that the balloon confronting faces of flanges 13 1 and 132 lie flush with the surfaces 124 and 125 of the magnets.

Annular magnets 116 and 117 may be made, for example, of Index 1, a sintered ceramic material having as basic ingredients barium carbonate and iron oxide. Index 1 is made by The Indiana Steel Products Company, Valparaiso, Indiana. Such magnets are magnetized with an even number of poles on their confronting faces. Magnets with four poles have proved to be satisfactory, although other numbers of poles suchas two, six, or eight may be used. Ceramic magnets such as Indox are sometimes preferred to Alnico magnets be cause of the economy, lightness, and tenacity of retention of magnetization of such ceramic magnets.

Preferably, as in Figs. 9 and 1-0, the device of Figs. 11 and 12 is employed with part-spherical outer and inner balloon guards 134 and 135, which are shown as made of a plastic material. The balloon-confronting ends of elements 121 and 122 extend through openings 136 and 137, so that surfaces 124 and 125 of the elements 121 and 122 lie flush with the inner surfaces of the respective guards 134 and 135.

Whereas I have shown and described preferred embodiments of the strand twisting and/or plying apparatus and method of the invention, it will be understood that such embodiments are illustrative only, and that the invention is capable of numerous variations as to details. Thus the magnetic coupling means may be located at positions other than that of generally the largest girth of the balloon. The coupling means may, for example, be mounted either near the apex of the ballon or near the ballooncreating fiyer. In such two other manners of mounting the coupling means, one element thereof is mounted inside the balloon and the otherelement thereof is mounted outside the balloon. Preferably in these cases the coupling means rotates about the axisof the balloon. When positioned near the axis of the flyer, the 'fiyer may be made of'electrically non-conducting material (to avoid the creation of eddy currents) and the fiyer and generally radially extending run of the strand guided thereby rotate in the gap between the two-elements of the magnetic coupling. 7

Although the magnetic coupling means of the invention "has been shown in certain illustrative embodiments '7 1'2 and has been described above as synchronizing two strand metering means located, respectively, inside and outside the balloon of a skip type plying spindle, it is to beunderstood that such magnetic coupling means is capable of other applications in connection with ballooncreating twisting spindles.

Thus the magnetic coupling may be employed to transmit motion for adjusting or controlling from outside the balloon a controllable part located inside the ballon balloon a controllable part located inside the balloon while the spindle is in operation. One exampleof such use is with a two-for-one twisting spindle of the uptwister type carrying a strand supply package or strand storage means and employing a back tension imposing device within the balloon controllable or adjustable as by means of a thumb screw. The magnetic coupling of the invention may have its inner magnetic element rotatably mounted on the package-supporting platform within the balloon and be suitably connected to the thumb screw of the tension device so that rotation of the inner magnetic element turns the thumb screw and controls or adjusts the tension device. The inner magnetic element can be turned by turning the outer magnetic element, which is located outside the balloon and is magnetically coupled to the inner magnetic element, even though the existence of the balloon prevents the direct manual adjustment of the thumb screw.

The magnetic coupling of the invention may also be used to advantage in controlling the inner variable speed take up mechanism of a'two-for-one take-up or downtwisting spindle generally of the type shown in applicants Patent No. 2,729,932. 'Motion from outside the balloon may be transmitted to within the balloon by the magnetic coupling; such motion may be used manually or automatically to adjust the speed of the variable speed take up capstan, which forwards the strand to the bobbin or strand storage means, whereby to maintain the balloon within predetermined limits of diameter. The invention is, therefore, to be defined by the scope of the claims appended hereto.

This application is a continuation in part of application Serial No. 598,597, filed July 18, 1956, now abandoned.

I claim as new the following:

1. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-oft strand package in a run extending to a plying junction, feeding asecond strand from a source of strand supply from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof'in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, and taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction.

2. The method of plying together two strands to form a tow ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a ballon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of theplying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plyingjunction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plyingjunction, and increasing the tension of one of said strands between the zone of its retardation and the plying junction when the tension of the other strand between itszone of retardation and the ply- "ing junction decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

3. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-01f strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and thenfrom the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, passing the two strands at equal speeds through their respective zones of retardation, taking up the plied strand un der tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, and increasing the tension of one of said strands between the zone of its retardation and the plying junction decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

4. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-olf strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction and to withdraw the plied strand from the plying junction, maintaining the sum of the retardations on the two strands constant, and increasing the tension of one of said strands between the zone of its retardation and the plying junction when the tension of the other strand between its zone of retardation and the plying junction decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

'5. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then' from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, passing the two strands at a predetermined speed ratio through their respective zones of retardation, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction and to withdraw the plied strand from the plying junction, maintaining the sum of the retardations on the two strands constant, and increasing the tension of one of said strands between the zone of its retardation and the plying junction when the tension of the other strand between its zone of retardation and the plying junction decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

6. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junc- I tion, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, and increasing the tension of one strand in the run thereof immediately after it has passed its zone of retardation when the tension of the other strand in the run thereof immediately after it has passed its zone of retardation decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

7. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the I plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, maintaining the sum of the retardations on the two strands constant, and increasing the tension of one strand in the run thereof immediately after it has passed its zone of retardation when the tension of the other strand in the run thereof immediately after it has passed its zone of retardation decreases, and decreasing such tension of the one strand when the said tension of the other strand increases. 8. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in ad Vance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, passing the two strands at equal speed through their respective zones of retardation, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, maintaining the sum of the retardations on the two strands constant, and increasing the tension of one strand in the run thereof immediately after it has passed its zone of re tardation when the tension of the other strand in the run thereof immediately after it has passed its zone of retardation decreases, and decreasing such tension of the one strand when the said tension of the other strand increases.

9. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-off strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, and exchanging energy between the two strands at their zones of retardation so that the two strands pass at a predetermined speed ratio through I- then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, maintaining the sum of the retardations on the two strands constant, and exchanging energy between the two strands at their zones of retardation so that the two strands pass at equal speeds through their respective zones of retardation.

11. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of a first strand, a support carrying a let-01f strand package, means comprising a revolving shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together, a first retarded feeding means for feeding the first strand at variable speed into the balloon, a second retarded feeding means for feeding the second strand at variable speed toward the plying junction where the .two strands are plied together, and means effectively connecting the first and second feeding means to cause them to feed their respective strands at apredetermined speed ratio.

12. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of a first strand, a support carrying a let-.oif strand package, means comprising a revolving shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together, a first retarded variable speed rotatable feeding means for feeding the first strand at variable speed into the balloon, a second retarded variable speed rotatable feeding means for feeding the second strand at variable speed toward theplying junction where the two strands are plied together, and means effectively connecting the first and second feeding means to cause them to feed their respective strands at a predetermined speed ratio.

13. Mechanism for twisting together two strands so as to forma two-ply strand, comprising a sourceof a first strand, a support carrying a let-off strand package, means comprising a revolving shaft operable 'to rotate a balloon of the first strand about the let-01f package and also to ply the two strands together, a first feeding means driven bythe travel of the first strand therepast for feeding the first-strand into the balloon, a secondfeeding means driven by'the travel of the second strand therepast for feedingthe second strand toward the plying junction where the two strands are plied together, and means connecting'the first and second feeding means to cause them to feedtheir respective strands at a predetermined speed ratio.

14. Mechanism for twisting together two strands was to form a'two-ply strand, comprising a source of a first strand, a support carrying a let-off strand package,-means comprising a revolving shaft operable to rotate a balloon of the first strand about the let-off package and also to ply the two strands together, a first feeding means driven by the travel of the first strand therepast for feeding the first strand into the balloon, a second feeding meansdriven by thetravel of the second strand therepast for feeding the second strand toward the plying junction where the two strands are plied together, .means connecting thefirst and second feeding means tocause themto feed their respective strands at a predetermined speedratio, and a third feeding means driven in synchronism with the revolving shaft for pulling the plied strand away from the plying junction and the strands past their feeding means.

.15. .Mechanism for twistingtogether two strands so as to form a two-ply strand, comprising a source of a first strand, a support carrying a let-off strand package, means comprising arevolvingshaftoperable to rotate a balloon of the firststrand about the let-off package and also to PlYthe itwostrandstogether, afirst feeding means driven by the travel of the first Strand therepastfor governing the speed. of feeding of the first stran into the balloon, a second feeding means driven by the travel of the second strand therepast for governing the speed of feeding of the second strand toward the plying junction where the two strands are plied together, and means operating to correlate the speeds of feeding of the first and second feeding means to cause them to feed their respective strands at a predetermined speed ratio, and a third feeding means for pulling the plied strand away from the plying junction and the two strands past their respective feeding means.

16. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of a first strand, a support carrying a letoif strand package, means comprising a revolving shaft operable to rotate a balloon of the first strand about the let-ofi package and also to ply the two strands together, a first retarded feeding means driven by the travel of the first strand therepast for governing the speed of feeding of the first strand into the balloon, a second retarded feedin means driven by the travel f the eco s an t e epa t f verni the ed of feeding f the e o d strand t ar th p ng iu n he e he two st a d ar pl ed sse he ans mea s rt n t co re a e h speed feeding of t e fir t and on d n means to'sa s t an t f ed the r r pe tive Strands a he am s eed and a third pnstant ed ng e s pul i t e rliedst and ar a fis e plying junction .and the two strands past their respective feeding means.

17. Mechanism for twisting together two strands so as to form a two-plystrand, comprising a source of a first strand, a support carrying alet-oif strand package, means comprising a revolving shaft operable to rotate a balloon of the first strand about the'let-ofi package and also to ply the two strands together, a first retarded feeding means driven by the travel of the first strand therep ast for feeding the first strand into the balloon, a second retarded feeding means driven by the travel of the second strand therepast for feeding the second strand toward the plying junction where the two strands are plied together, means connecting the first and second feeding means to cause them to feed their respective st-r-ands at a predetermined speed ratio, and a third feedingmeans driven in synchron ism with the revolving shaft for pulling the plied strand away from the plying junction, for pulling the .first strand past the :first feeding means .and into and .through the balloon, and for pulling the second strandpast the second feeding means.

18. Mechanism .foratwisting together twostrands so as to form a two-p1y strand, comprising a source of a first strand, a support carryinga let-01f strand package, means comprising a revolving shaft operable to rotate a balloon of the first strand about the leteoff package and also to ply the two strands together, a first retarded feeding means driven by the travel of .the first strand :therepast for feeding the first strand into @the balloon, a second retarded-feedingmeans drivenfbycthe :travel of the. second strand therepastfor feeding the second strand --toward-the plying junction where the two strands are plied together, means connecting the first and .second feeding means to cause them :to :feedtheir respective strands at/the same speed, and a third feeding means driven in synchronism with the revolving .shaft for pulling :thepliedstrand away from the plying junction, for pulling .the -firststrand past the first feeding means and into and through the balloon, and for pulling the secondstrand past the second feeding means. i

19. A strand twisting spindlehaving a strand storage means thereon, means comprising ,a rotatable shaft for rotating a strand to form a strand'balloon about the strand storage means,.r neans;for driving theshafnmeans within the .balloon for at least partially governing the pe d of t a e .Q a .st andexten as-withi the b l d-ex n n to th t andstoras means se a a means t ide th .bal p independent y s a plling th s ran s d soveminsmesns; aa -ma edr v us y n- 17 meeting the controlling and governing means through the zone traversed by the rotating strand;

20. A strand twisting spindle having a revolving shaft, said shaft rotating a strand to form a strand balloon, means for driving the shaft, means within the balloon for at least partially governing the speed of travel of a strand extending Within the balloon, separate means outside the balloon for independently controlling the strand speed governing means, and means acting through the zone traversed by the rotating strand for drivingly connecting the controlling and governing means.

21. A strand twisting spindle having a revolving shaft carrying a strand storage means thereon, said shaft rotating a strand to form a strand balloon about the strand storage means, means to drive the shaft, means within the balloon for at least partially governing the speed of travel of a strand located within the balloon and extending to the strand storage means, separate means outside the balloon for independently controlling the strand speed governing means, and means acting through the zone traversed by the rotating strand for drivingly connecting the controlling and governing means.

22. A strand twisting spindle having a revolving shaft carrying a stationary support bearing a strand storage means thereon, said shaft rotating a strand to form a strand balloon about the support and strand storage means, means to drive the shaft, means on the support for at least partially governing the speed of travel of a strand extending to the strand storage means, separate means outside theballoon for independently controlling the strand speed governing means, and means drivingly connected the controlling and governing means through the zone traversed bythestrand balloon.

23. A strand twisting spindle, comprising means for rotating a strand to form a strand balloon, controllable mechanism within the balloon, and means for controlling such mechanism from outside the balloon during operation of the spindle, said last named means comprising a first rotatable magnetic element located inside the balloon and connected to the controllable mechanism, a second rotatable magnetic element located outside the balloon and magnetically locked to the first magnetic element for joint rotation therewith, and means for tuming the second magnetic element whereby to control the controllable mechanism.

24. A strand twisting spindle having a revolving shaft carrying a stationary support bearing a strand storage means thereon, said shaft rotating a strand to form a strand balloon about the support and strand storage means, strand-tensioning means on the support for at least partially governing the speed of travel of a strand located within the balloon and extending to the strand storage means, said strand-tensioning means having a rotatable element, means outside the balloon for controlling the rotatable elernent of the strand speed governing means, magnetic means outside the balloon connected to the controlling means, magnetic means inside the balloon connected to the rotatable element of the governing means, said two magnetic means lying spaced apart to receive the rotating balloon-forming strand between them and having a magnetic field between them locking the controlling means and the rotatable element of the governing means together for joint rotation.

25. A strand twisting spindle having a revolving shaft carrying a stationary support bearing a strand storage means thereon, said shaft creating and maintaining a strand balloon about the support and strand storage means, means on the support for governing the speed of travel of a strand extending to the strand storage means, said governing means including a first rotatable shaft within the balloon, a second rotatable shaft outside the balloon and aligned with the first shaft for controlling the strand speed governing means, magnetic means outside the balloon connected to the controlling means, magnetic means inside the balloon connected to the governv 18 ing means, said two magnetic means lying spaced apart to receive the balloon between them and having a magnetic field between them looking the first and second shafts together for joint rotation.

26. A strand twisting spindle having a revolving shaft carrying a stationary support bearing a strand storing means thereon, said shaft rotating a strand to form a strand balloon about the support and strand storing means, means on the support for governing the speed of travel of a strand extending to the strand storing means, means outside the balloon for controlling the strand speed governing means, magnetic means outside the balloon connected to the controlling means, magnetic means inside the balloon connected to the governing means, said two magnetic means lying spaced apart to receive the rotating strand between them and having a magnetic field between them for locking the controlling means and the governing means together for joint rotation.

27. A strand twisting spindle having a revolving shaft carrying a stationary support bearing a strand storing means thereon, said shaft creating and maintaining a strand balloon about the support and strand storing means, means on the support for governing the speed of travel of a strand extending to the strand storing means, means outside the balloon for controlling the strand speed governing means, magnetic means outside the balloon journalled to rotate about a fixed axis and connected to the controlling means, magnetic means inside the balloon journalled on the suppont and con nected to the governing means, said two magnetic means lying spaced apart to receive the balloon between them and having a magnetic field between them locking the controlling means and the governing means together for joint rotation, said two magnetic means being coaxial and disposed with their common axis lying generally at right angles to the axis of rotation of the balloon and functioning at least to aid in maintaining the support from rotation with the shaft.

28. In a balloon-creating strand twisting spindle having a balloon governing means located inside the balloon, the improvement which comprises means for controlling the governing means during operation of the spindle, said last named means comprising a first rotatable magnetic means inside the balloon and confronting the inner surface thereof connected to the governing means, a second rotatable magnetic means outside the balloon and confronting the outer surface thereof connected to the controlling means, the two magnetic means confronting each other and 'being spaced apart to receive the balloon between them, the magnetic means having a magnetic field between them which locks them together for joint rotation.

29. The method of plying together two strands to form a two-ply strand comprising feeding a first strand from a let-oif strand package in a run extending to a plying junction, feeding a second strand from a source of strand supply into a balloon rotating about the strand package and then from the balloon to the plying junction, yieldingly retarding the first strand at a zone thereof in advance of the plying junction, yieldingly retarding the second strand at a zone thereof in advance of the balloon, taking up the plied strand under tension beyond the plying junction, such taking up serving to overcome the yielding retardation of the two strands, to forward the two strands to the plying junction, and to withdraw the plied strand from the plying junction, and passing the two strands at equal speeds through their respective zones of retardation.

30. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of a first strand, a support carrying a let-01f strand package, a revolving shaft operable to rotate a balloon of the first strand about the let-oif package and also to ply the two strands together, a first idle rotatable feeding means for feeding the first strand into the balloon, a second idle '19 rotatable feeding means for feeding the second strand toward the plying junction where the two strands are plied together, and means controlling the first and second feeding means to cause them to feed their respective strands at a predetermined speed ratio.

31. Mechanism for twisting together two strands so as to form a two-ply strand, comprising a source of a first strand, 3. support carrying a let-off strand package, a revolving shaft operable to rotate a balloon of the first strand about the let-ofi package and also to ply the two strands together, a first retarded feeding means driven by the travel of the first strand therepast for feeding the first strand into the balloon, a second retarded feeding means driven by the travel of the second strand therepast for feeding the second strand toward the plying junction where the two strands are plied together, means controlling the first and second feeding means to cause them to feed their respective strands at a predetermined speed ratio, and means operative upon a change in tension of one of the strands between its feeding means and the plying junction to change the sum of the retardations imposed on the two strands by their feeding means.

32. A strand twisting spindle, comprising means for rotating a strand to form a strand balloon, controllable mechanism within the balloon, and means for controlling such mechanism from outside the balloon during op'eration of the spindle, said last named means comprising a 1 to travel between them, and disposed with their commonaxis lying generally at right angles to the axis of rotation of the balloon.

33. A strand twisting spindle having a hollow revolvingfirst shaft, said first shaft rotating a strand to form a rotating strand loop having a run extending generally radially of the first shaft, means for driving the first shaft, means within the loop for at least partially governing the speed of travel of a strand extending within the loop, separate means outside the loop for independently controlling the strand speed governing means, and means acting through the zone traversed by the rotating strand for drivingly connecting the controlling and governing means, said last named means comprising a second shaft positioned coaxially of the first shaft and extending into the first shaft to a location short of the generally radial run of the loop, a third shaft coaxial of the second shaft positioned within the loop and drivingly connected to the controlling and governing means, one end of the third shaft extending into the first shaft to a location short of the generally radial run of the loop, and gear means rotatably mounted on the first shaft drivingly connecting the second and third shafts.

References Cited in the file of this patent UNITED STATES PATENTS 2,503,242 Clarkson Apr. 11, 1950 2,732,680 Vibber Jan. 31, 1956 2,736,160 Vibber Feb. 28, 1956 2,737,773 Clarkson Mar. 13, 1956 FOREIGN PATENTS 563,746 Germany Nov. 9, 1932 

